The overall goal is to provide a theory of memory in nonverbal primates. The initial strategy involves testing classes of models in paradigms where differential predictions are generated and gathering other data designed to facilitate the development of theories. Major focal points concern selective coding of information in memory, rehearsal processes, relationships between short- and long-term memory, and practice and transfer effects. Considerable use will be made of mathematical modeling and computer simulation methods to aid in interpreting data. Experimental studies fall into four main categories: 1) examinations of the transfer of memory skills and the development of selective coding of information, 2) comparisons of stimulus properties, interference, and rehearsal opportunities over brief retention intervals to ask questions about short-term memory functioning, 3) assessments of the large practice effects observed in short-term memory paradigms, and 4) studies of repetition and spacing effects in both discrimination learning and delayed-matching-to-sample paradigms.